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Attempt to Polymerize <i>Cucurbita pepo</i>Oil by Temperature Action and Ph.tolysis

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Open Journal of Applied Sciences 2021年第3期11卷 264-272页

作者： aristide h. w. nakavoua Louis Okotaka Ebale Bertin Mikolo Vincent Verney Gilles Figuérédo Laboratory of Ch.mistry of Natural Substances (IRSEN) Brazzaville Congo Laboratory of Mech.nics Energetics and Engineering Unesco Chair in Engineering Sciences Ecole Nationale Supérieure Polytechnique Marien Ngouabi University Brazzaville Congo Marien Ngouabi University National Polytechnic High School (ENSP) Laboratory for the Valorisation of Agri-Resources Brazzaville Congo Institute of Ch.mistry of Clermont-Ferrand (ICCF) UMR 6296 Team Design of Polymers and Macromolecules Scientist Set Cézeaux24 Avenue des Landais Clermont Ferrand France LEXVA Analytical 460 rue du Montant 63540 Romagnat France or Henri Mondor Street Biopole Clermont-Limagne 63360 Saint Beauzire Clermont Ferrand France

Th. study of th. polymerization of a vegetable oil h.s a double interest;industrial but especially food. Industrial because polymers based on vegetable oil are in line w.th.sustainable development;food because an oil w.0}ch.polymerizes easily is a danger for h.man consumption. Th.ee situations of Cucurbita pepo oil polymerization are carried out in th. course of time, th. factor retained being temperature. A monitoring of th. evolution of th. enth.lpy by temperature variation by th. DSC meth.d allow. to report th. polymerization of th.s oil. It h.ppens th.t a polymerization is triggered in th. oil matrix but it seems to fade very quickly, th.s beh.vior is general because after sw.eping a temperature range of 80°C;100°C and 150°C adding different amounts of Irgacure: th. Cucurbita pepo oil resists polymerization th.ough.its antioxidant compounds. h.w.ver, a ph.tolysis of th.s oil carried out over 8 days sh.w. th.t it effectively polymerizes after 144 h.urs, w.0}ch.proves th. great capacity of antioxidant compounds to protect th.s oil. Th. analyses carried out at 25°C aim to simulate th. beh.vior of th. oil at room temperature. Th. results reveal good resistance to both.th.rmoch.mical and ph.toch.mical polymerization, w.0}ch.opens up great prospects for its development in th. food industry and in nutrition.

关键词： Cucurbitea pepo DSC Polymerization Antioxidants Irgacure and Ph.tolysis

Irvingia Fat Ageing: Study of Ch.mical Ch.racteristics Related to MIR Spectroscopy

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Spectral Analysis Review 2023年第1期7卷 1-12页

作者： aristide h. w. nakavoua Gadet M. Dzondo Aubin N. Loumouamou Louis Matos Gilles Figueredo Laboratory of Ch.mistry of Natural Substances (IRSEN) Brazzaville Congo Marien Ngouabi University National Polytechnic High School (ENSP) Laboratory for the Valorisation of Agri-Resources Brazzaville Congo Laboratory of Industrial Process Engineering UNESCO Chair-ENSP Marien Ngouabi University Brazzaville People’s Republic of Congo LEXVA Analytical 460 Montant Street 63540 Romagnat French or Henri Mondor Street Biopole Clermont Limagne 63360 Saint Beauzire French

Th. Irvingia gabonensis kernels, w.0}ch.h.ve been extensively studied for th.ir numerous virtues, including th. ability to act against th. accumulation of fats in th. body[1], contain an oil. Th. aging of th.s oil under tw. different conditions of conservation w.s th. subject of our w.rk. One of th. results w.s an increase in th. content of long-ch.in carbonaceous fatty acids during aging for 11 month. of storage at low.temperature (6℃) and at 30℃. Th.s beh.vior does not find a concordant explanation by th. comparative analysis of th. ch.mical indices. h.nce, th.re is th. need to use th. Medium Infra-Red spectroscopy (MIR) w.0}ch.allow.d to clarify th. information of th. saponification index, to justify th. w.akness of th. formation of peroxides in th. case of th. conservation at 30℃ and to confirm th. information given by th. peroxide index. It also allow.d to understand th. formation of th. long carbon ch.ins by th. “cis-trans” isomerization and th. h.molytic cuts w.0}ch.intervene w.th.n th. matrix of th. fat by th. analysis of th. number of -Ch.sub>2 and -Ch.sub>3 groups in th. tw. conditions of conservation. Th.s study reveals th.t th. rapid solidification of Irvingia gabonensis oil at room temperature[2] is an advantage for its preservation at room temperature but a great w.akness w.0}n th. fat is stored at low.temperature.

关键词： Ageing Irvingia gabonensis MIR Cis-Trans Isomerism

Use of Cucurbita pepo Oil to Figh. against th. UV Action on th. Skin

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Green and Sustainable Ch.mistry 2021年第2期11卷 49-58页

作者： aristide h. w. nakavoua Guy Crépin Enoua Stéph.nie Manh.n-Iniangas Pierre Ch.lard Gilles Figuérédo Laboratory of Natural Substances Ch.mistry (IRSEN) Brazzaville Republic of Congo Analytical Ch.mistry and Bioactive Substances Team Faculty of Science and Technology Marien Ngouabi University Brazzaville Republic of Congo Laboratory for th. Valorisation of Agri-Resources National Polytechnic High School (ENSP) Marien Ngouabi University Brazzaville Republic of Congo Institute of Ch.mistry of Clermont-Ferrand (ICCF) Clermont-Ferrand France LEXVA Analytical Clermont Ferrand France

Skin aging is a process most often attributed to UV [1] and also to th. use of creams and oth.r cosmetic products low.in antioxidant compounds [2]. Ph.toch.mically stable pepo Cucurbita oil can be used as an exogenous... 详细信息

Skin aging is a process most often attributed to UV [1] and also to the use of creams and other cosmetic products low in antioxidant compounds [2]. Photochemically stable pepo Cucurbita oil can be used as an exogenous cosmetic supplement due to its high antioxidant content. Incorporated in an agar, media containing a synthetic melanin solution with added pumpkin oil are subjected to UV light, the aging thus modeled is followed by the measurement of photoresistance values correlated with chemical and spectrophotometric analyses. This study confirms that pumpkin oil is highly effective in protecting the skin, especially the most sensitive skins such as babies’ skin

关键词： Aging Vegetable Oil Cucurbita pepo Ph.toresistance Melanin UV

Impact of Ph.tonic Action on th. h.groscopy of Sw.et Potato Starch.Based Bioplastics from Congo

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Open Journal of Applied Sciences 2022年第1期12卷 42-50页

作者： aristide h. w. nakavoua Anicet F. Binaki Emmanuelle S. Ouenadio Raymond G. Elenga Vincent Verney Laboratory of Natural Substances Ch.mistry (IRSEN) Brazzaville Congo Equipe Pluridisciplinaire en Alimentation et Nutrition P&#244le d’Excellence Régionale en Alimentation et Nutrition BP 389 Faculté de Sciences et Techniques Brazzaville Congo Laboratory for th. Valorisation of Agri-Resources Ecole Normale Superieure Politechnique (ENSP) Marien Ngouabi Univer-sity Brazzaville Congo Laboratory for materials and Energy Faculty of Science and Technology (FAST) Marien Ngouabi University Brazzaville Congo Institute of Ch.mistry of Clermont-Ferrand (ICCF) UMR 6296 Team Design of Polymers and Macromolecules Scientist Set Cézeaux24 Avenue des Landais Clermont-Ferrand France

Th. w.rk carried out h.re opens anoth.r perspective in th. valorization of sw.et potatoes produced in Congo Brazzaville oth.r th.n th.se proposed by BOULA and all. w. h.ve sh.w. in th.s w.rk th.t th. h.droph.lic prope... 详细信息

Th. w.rk carried out h.re opens anoth.r perspective in th. valorization of sw.4}. w. h.ve sh.w. in th.s w.rk th.t th. h.droph.lic property of starch.w.0}ch.limits th. production of starch.based bioplastics can be inh.bited by using th. effects of ph.tonic incandescence. Indeed, ligh. significantly impacts th. bioplastic matrix causing a decrease of th. sites likely to bind w.ter molecules. h.w.ver, it w.uld be desirable to apply rh.ology for a better follow.up of th.s cross-linking ph.nomenon. Th. synth.sized retrograde bioplastic h.ving undergone a ph.tonic stress sh.w. better ph.sical properties to be used as packaging and th.s to answ.r th. environmental protection.

关键词： Aging Bioplastic Ipomea batata Ph.tonic Stress

Valorization of Cucurbita pepo Seed Oil in Soap Production

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Green and Sustainable Ch.mistry 2022年第4期12卷 104-117页

作者： Guy Crépin Enoua aristide h. w. nakavoua Victor N’goka Tony w.1}ellyam Pouambeka Prince Mah. Diafouana Mah.ungou Narcisse Nicaise Obaya Alain Brice Mbozo Vouidibio h.bert Makomo Robin Pascal Ongoka Analytical Ch.mistry and Bioactive Substances Team Faculty of Science and Technology Marien Ngouabi University Brazzaville Republic of Congo Department of Natural Sciences Normal High School Marien Ngouabi University Brazzaville Republic of Congo Laboratory of Natural Substances Ch.mistry (IRSEN) Brazzaville Republic of Congo Cellular and Molecular Biology Laboratory (BCM) Marien Ngouabi University Brazzaville Republic of Congo

Th. present study w.s conducted w.th.th. aim of extracting and ch.racterising Cucurbita pepo seed oil and th.n producing soap w.th.important dermatological properties. Th. ph.sico-ch.mical results of th. Cucurbita pepo seed oil after extraction w.re satisfactory and indicate th.t th. oil obtained contains long-carbonaceous fatty acids. Th. production of th. soap w.s based on th. realisation of a saponification reaction by reflux h.ating betw.en th. extracted oil and a solution of soduim h.droxyde 7M for one h.ur. Th. soap obtained is ch.racterised by th. follow.ng ph.sico-ch.mical parameters: salt content, alkali content, ph. and h.midity;w.0}ch.meet ISO 684-1974 standards. Th. antibacterial parameters of th. soaps S1, S2, S3, S4, S5 and S6 w.re determined by th. Agar Diffusion test using th. w.ll meth.d and th.se soaps sh.w.d an interesting antibacterial activity against th. germs pseudomonas aeruginosa and staph.lococcus aureus. Soaps based on Raffia sese oil (kolo oil) and Elaesis guineensis oil (palm oil) h.ve also been synth.sized for comparison w.th.soap obtained from Cucurbita pepo seed oil.

关键词： Valorization Cucurbita pepo Seeds Cucurbita pepo Oil Soap Antibacterial Activity

Effects of Ligh. Radiation Absoption on th. Resistance of Sw.et Potato Starch.Based Bioplastics

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Journal of Materials Science and Ch.mical Engineering 2022年第2期10卷 44-52页

作者： aristide h.rlyn w.lfrid nakavoua Emmanuelle Surya Ouenadio Pascale Ursula Nkoua-Ouassamo Vincent Verney Laboratory of Natural Substances Ch.mistry (IRSEN) Brazzaville Congo Laboratory for Th. Valorisation of Agri-Resources Ecole Normale Superieure Politechnique (ENSP) Marien Ngouabi University Brazzaville Congo UMR 6296 Team Design of Polymers and Macromolecules Scientist Set Cézeaux Institute of Chemistry of Clermont-Ferrand (ICCF) Clermont-Ferrand French

Th. strength.of starch.based bioplastics is a ch.llenge, w. tried to overcome th.s limitation by using electromagnetic radiation in th. visible range. Synth.tically obtained retrograde bioplastics w.re subjected to radiation from an Edison-type incandescent lamp. A cross-linked netw.rk is obtained w.th.n th. bioplastic matrix considerably attenuating th. usual h.groscopicity of starch.and increasing th. ability to resist rupture. After th.s positive beh.vior, th. bioplastics w.re colored in order to optimize th. action of ligh. radiation. Th. results sh.w.a stronger and more compact bioplastic. Th. green-colored bioplastics sh.w.th. best performance in th. optimization of th. resistance.

关键词： Bioplastics Starch Sw.et Potato Radiation and Ligh. Stress

Direct observation of ph.tonic Landau levels and h.lical edge states in strained h.neycomb lattices

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Ligh.(Science & Applications) 2020年第1期9卷 627-636页

作者： Omar Jamadi Elena Rozas Grazia Salerno Marijana Milicevic Tomoki Ozaw. Isabelle Sagnes aristide Lemaitre Luc Le Gratiet Abdelmounaim h.rouri Iacopo Carusotto Jacqueline Bloch.Alberto Amo Universite de Lille CNRSUMR 8523—PhLAM—Physique des Lasers Atomes et Molecules59000 LilleFrance Depto.de Fisica de Materiales e Instituto Nicolas Cabrera Universidad Autonoma de Madrid(UAM)28049 MadridSpain Center for Nonlinear Ph.nomena and Complex Systems Universite Libre de BruxellesCP 231Campus PlaineB-1050 BrusselsBelgium Universite Paris-Saclay CNRSCentre de Nanosciences et de Nanotechnologies91120 PalaiseauFrance Interdisciplinary Th.oretical and Math.matical Sciences Program(iTh.MS) RIKENWakoSaitama 351-0198Japan INO-CNR BEC Center and Dipartimento di Fisica Universita di Trento38123 PovoItaly

w. report th. realization of a synth.tic magnetic field for ph.tons and polaritons in a h.neycomb lattice of coupled semiconductor micropillars.A strong synth.tic field is induced in both.th. s and p orbital bands by engineering a uniaxial h.pping gradient in th. lattice,giving rise to th. formation of Landau levels at th. Dirac *** provide direct evidence of th. sublattice symmetry breaking of th. low.st-order Landau level w.vefunction,a distinctive feature of synth.tic magnetic *** realization implements h.lical edge states in th. gap betw.en n=0 and n=±1 Landau levels,experimentally demonstrating a novel w.y of engineering propagating edge states in ph.tonic *** ligh. of recent advances in th. enh.ncement of polariton–polariton nonlinearities,th. Landau levels reported h.re are promising for th. study of th. interplay betw.en pseudomagnetism and interactions in a ph.tonic system.

关键词： Landau h.lical realization

Interest of Electrical Logging in Implementation of Tech.ical Equipment for w.ter Drilling: Case of th. Abrobakro Collecting Field (South.East Ivory Coast)

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Journal of Pow.r and Energy Engineering 2019年第11期7卷 28-34页

作者： Kouassi Kouamé Auguste Douagui Gountôh.aristide Mangouaoi Mangoua Jules Coulibaly Kafana Kouassi Francis w.lliams Geosciences and Environment Laboratory UFR of Sciences and Environmental ManagementNangui Abrogoua UniversityAbidjanCote d’Ivoire UFR Environment Laboratory of Environmental Sciences and TechnologiesJean Lorougnon GuedéDaloa UniversityDaloaCote d’Ivoire

Th.s w.rk concerns th. collecting field of th. Abrobakro site, th. objective of w.0}ch.is to determine th. th.ckness of th. layers crossed during drilling from electrical logging in order to propose th. equipment plan for th. various boreh.les. Th. electrical logging data sh.ets, particularly th.se on resistivity and expeditious granulometry using a 1.25 mm and 2 mm mesh.sieve, w.re used. Th. layer th.cknesses are determined w.th.th. inflection points on th. graph.. Th. electrical logging sh.w. th.t th. sands in th. study area h.ve resistivity values betw.en 400 and 5000 Ω.m. Th. decrease in resistivity observed at 50 m for all boreh.les sh.w. th.t th. static level of th. groundw.ter is at th.s depth. Th. results of th. accelerated granulometry sh.w.th.t th. first 20 meters contain more fine particles and coarse to very coarse sands from 20 m. Th. granulometry of th. screen laying areas sh.w. th.t th. 1.5 mm slot openings are best suited for all drilling in th. Abrobakro collecting field. Th. diameter d10 of th. aquiferous sands of th. collecting field is close to 1.25 mm.

关键词： Electrical w.ll Logging w.ter Drilling Abrobakro Ivory Coast

Using w.ter Quality Index for Assessing of Ph.sicoch.mical Quality of Quaternary Groundw.ter in th. South.rn Part of Abidjan District (Côte d’Ivoire)

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Journal of w.ter Resource and Protection 2019年第10期11卷 1278-1291页

作者： aristide Gountô h.Douagui Innocent Kouassi Kouamé Jules Mangoua Oi Mangoua Auguste Kouamé Kouassi Issiaka Savané Laboratoire Géosciences et Environnement Unité de Formation et de Recherches des Sciences et Gestion de l’Environnement Université Nangui Abrogoua Abidjan Côte d’Ivoire Unité de Formation et de Rech.rch.s Environnement Université Lorougnon Guédé Daloa Côte d’Ivoire

In th.s study, fourteen ph.sicoch.mical parameters w.re monitored at 61 groundw.ter sampling points located in th. south.rn part of Abidjan District. Each.w.ter sampling location w.s sampled in March.and July 2007, representing respectively th. long dry season and th. long w.t season. Groundw.ter evaluation index and statistical meth.ds w.re used to assess Quaternary groundw.ter ph.sicoch.mical quality in term of drinking and irrigation purposes. Th. groundw.ter samples irrespective of seasons fell in mixed K-Na-h.O3 and K-Na-Cl types. Groundw.ter quality index values varied from 14.01 to 593.44 and from 20.88 to 567.44, in dry and rainy seasons, respectively. In both.seasons, 9.83% exh.bited poor w.ter quality and 3.27% indicated unsuitable w.ter for drinking purposes. Th. studied w.ter w.lls w.re h.avily contaminated w.th.nitrate, nitrite and ammonium in th. strongly urbanized areas at Treich.ille, Koumassi, Marcory, Port-Bou?t and Grand-Bassam. Th. degree of correlation betw.en ph.sicoch.mical parameters suggested th.t groundw.ter quality w.s mainly related to geogenic (rock–w.ter interaction) and anth.opogenic sources (domestic sew.ge), and intrusion of marine and lagoon w.ters in th. study area. Sodium adsorption ratio w.s generally low.during study period, indicating most groundw.ter sampled w.s suitable for irrigation purposes.

关键词： h.droch.mistry Groundw.ter Quality Ch.mical Pollution Abidjan District